The dynamics of population and production of Native Chicken under extensive- and semi-intensive maintenance

This study evaluated kampung chickens’ growth rate and production performance in extensive and semi-intensive rearing in Central Java, Indonesia. The survey method was employed for this study. The targets used in the study were kampung chicken farmers in the Banyumas and Kebumen areas. The survey method is carried out by collecting data, observing and measuring population, production performance, including meat and egg production. The data obtained, processed, and presented in the tables and graphs, calculated the population and production of chicken to evaluate its growth. The performance of chicken production, including egg production, egg weight, number of eggs hatched, and hatchability, was analyzed using general linear model (GLM) analysis. The result showed a 1.9% growth rate of the native chicken population, in which the hens outnumbered the roosters. The meat and egg production growth rates were 8.2% and 6.8%, respectively, between 2016 and 2020 in Central Java. Native chickens kept under semi-intensive maintenance produced more eggs than those in an extensive system. Conclusively, native chicken of Central Java experienced growth in population and production of meat and egg. The semi-intensive system, compared to the extensive system, had a higher rate of eggs production.

Statistical information on the socio-economic development of Bakhchisarai at the end of the 18th – beginning of the 20th centuries

The city of Bakhchisarai turned into a district town in the Tauride province after the annexation of the Crimea to the Russian Empire. This article analyzes the picture of urban life, including the dynamics of population growth, an increase in the number of religious and educational institutions, based on archival materials and statistics. Crimean Tatars supported the local traditions of craft production, based on the use of local and partly imported raw materials. Handicraft workshops and trade shops defined the trade and handicraft character of the eastern Islamic city. After the annexation of the Crimea to Russia the city’s industry has developed rapidly, the number of townspeople grew. The rates of development of trade and industrial establishments of Bakhchisarai are demonstrated, the specialization of the former capital as a trade and craft center is shown, on the basis of statistical collections. The city of Bakhchisarai gradually integrated into the economic, cultural and economic space of the Russian Empire.

Population immunity to SARS-CoV-2 virus in residents of the Irkutsk Region in the dynamics of the epidemic

Background. Currently, the COVID-19 pandemic in the world and in Russia remains the main event. In this regard, the study of the manifestations of the epidemic process of the new coronavirus infection COVID-19 and the patterns of its development are an urgent area of research. In the fight against this viral disease, an important role is assigned to the study of the development of population immunity to the SARSCoV-2 virus, which will make it possible to assess the dynamics of seroprevalence and the formation of post-infectious humoral immunity, forecasting the development of the epidemiological situation, elucidating the characteristics of the epidemic process, and will also contribute to planning activities for specific and non-specific prevention of the disease.The aim: to determine the dynamics of population immunity to SARS-CoV-2 among the population of the Irkutsk region during the COVID-19 pandemic.Materials and methods. As a part of the Rospotrebnadzor project of assessing population immunity to SARS-CoV-2 in the population of the Russian Federation, the research has being conducted among the population of the Irkutsk region in the periods from June 23, 2020 to July 19, 2020 (Stage 1), from September 16, 2020 to September 25, 2020 (Stage 2), from December 7, 2020 to December 18, 2020 (Stage 3) and from March 8, 2021 to March 14, 2021(Stage 4), taking into account the reacted one recommended by the WHO. The content of antibodies to SARS-CoV-2 was determined by ELISA using a set of tests for human serum or plasma for specific immunoglobulins of class G to the proteins of the SARS-CoV-2 coronavirus.The results. The research of the humoral immunity of volunteers shows that during the period of an epidemic rise in the incidence of COVID-19 in the Irkutsk region, a low level of seroprevalence was formed (Stage 1 – 5.8 ± 0.5 %, Stage 2 – 12.1 ± 0.7 %), and in conditions of a long-term maximum increase in the incidence rate – 25.9 ± 1.0 % (Stage 3) and 46.2 ± 1.2 % (Stage 4). A significant proportion (Stage 1 – 82.2 ± 3.2 %, Stage 2 – 86.1 ± 2.3 %) of asymptomatic forms of infection characterizes the high intensity of the latently developing epidemic process in the first two stages. High levels of IgG in reconvalescents of COVID-19 persisted for an average of 3 to 5 months.Conclusion. The results of assessing the population immunity to the SARS-CoV-2 virus in the population of the Irkutsk region indicate that the seroprevalence level at Stage 4 of the research was 46.2 %. After the disease, on average, 49.5 % of persons did not detect antibodies. The results obtained should be taken into account when organizing preventive measures, including vaccination, and predicting morbidity.

Evolution of reduced dormancy during range expansions

There is increasing evidence that life-history traits can evolve rapidly during range expansion and that this evolution can impact the ecological dynamics of population spread. While dispersal evolution during range expansion has received substantial attention, dormancy (dispersal in time) has not. Here, we use an individual-based model to investigate the evolution of seed dormancy during range expansion. When a population is at spatial equilibrium our model produces results that are consistent with previous theoretical studies: seed dormancy evolves due to kin competition and the degree of dormancy increases as temporal environmental variation increases. During range expansions we consistently observe evolution towards reduced rates of dormancy at the front. Behind the front there is selection for higher rates of dormancy. Notably, the decreased dormancy towards the expanding margin reduces the regional resilience of recently expanded populations to a series of harsh years. We discuss how dormancy evolution during range expansion, and its consequences for spatial population dynamics, may impact other evolutionary responses to environmental change. We end with suggestions for future theoretical and empirical work.

Scenarios for development of the settlement systems of Siberia and Russian Far East until 2030

The subject of the study is the settlement systems of the Siberian and the Far East Federal Districts. This article considers the settlement system not only in the context of the spatial organization of society and the territorial organization of productive forces, but also as a derivative of the economic model of the State. Data on the dynamics of population size and density, migration indicators for the subjects of macroregions are presented, and regional types of settlement systems are structured. The importance of a qualitative change in the system of population placement in Siberia and the Far East for creating an internationally competitive network of settlements is emphasized. Within the frame of the main prospects for transformation of the Russian settlement system and its ordering there are considered perspective scenarios: "Priority" (active State regulation of settlement), "Progressive" (free self-organization of settlement) and "Inertial" (mixed transformation of settlement systems). In view of this, the typology of the "second" and "third" cities in the Siberian and Far East regions is given as a complex basis for spatial or supporting frameworks of settlement systems.

Small and Medium-Sized Towns in the Settlement System of the Russian North: 1939–2020

The article examines the settlement system of the Russian North, which was previously determined by decisions of ministries and departments, and now it is changing under the influence of resource corporations' activities. The focus is on small and medium-sized towns that are part of the supporting framework of settlement, ensuring connectivity of the northern territories. The authors analyze the dynamics of population, including urban one, and the population of small and medium-sized cities. The study identifies periods of upward and downward dynamics for each population group and settlements. If the country is drawing the population to the west, then in the North it is concentrated in the Asian part. The article shows that urban settlements were created multifunctional, with the monopoly of a city-forming enterprise, which, on the one hand, made them economically vulnerable, and on the other hand — more adaptable to external conditions. According to the author's methodology, small and medium towns are ranked according to the share of the population of these cities in the total population of the region. The authors have identified four groups of regions that have an insufficient, medium, high and excessive share of the population of small and medium towns; the optimal boundaries of this share are proposed. The authors have identified four groups of regions that have an insufficient, medium, high and excess share of the population of small and medium towns; the optimal boundaries of this share are proposed. The study revealed the similarity (concentration of the population in large cities) and the difference in the structure of settlements in the North (the share of the population living in small and medium urban settlements, is lower in the countryside). The research results will be applied in the development of strategic documents for the development of northern towns.

Seasonal dynamics of population and age composition of the trematode Gynaecotyla adunca larvae (Linton, 1905) Yamaguti, 1939 in the Black Sea

The purpose of the research is analyzing the seasonal dynamics for the number and the hemipopulation structure of the trematode Gynaecotyla adunca larvae in shrimps of the genus Palaemon Weber, 1795 and determining the dependence of their infection with the metacercariae G. adunca on the host size and the season of the year in the water area of Sevastopol.Materials and methods. Samples of aquatic organisms were collected monthly during 2012 in two different biotopes, the estuary of the Chernaya River and the Kazachya Bay. We examined a total of 2,445 specimens of the Hydrobia acuta mollusk, 200 specimens of the Palaemon elegans shrimp in the estuary of the Chernaya River, and 2,248 specimens of the H. acuta mollusks and 64 specimens of P. adsepsus in the water area of Kazachya Bay. Shrimps were caught with a 1 × 0.4 m seine with a 6–8 mm mesh. The mollusks were collected with a hand grab sampler with a sampling area of 0.04 m2. The mollusks and shrimps were classified in accordance with the World Register of Marine Species. All mollusk and shrimp tissues were examined by the compression method under an MBS-10 binocular microscope. Descriptive statistics was calculated using Statistica 6 for Windows.Results and discussion. We have found that the parthenita G. adunca is characterized by asynchronous emergence of secondary sporocyst that contain cercariae, while the metacercariae G. adunca hemipopulation is characterized by an overdispersed distribution, which indirectly indicates a low density of the host population and its constant migration. We analyzed seasonal dynamics of the found microfallid larvae population. The metacercariae G. adunca are characterized by one peak of infection with trematodes in summer.

Fin whales of the Great Bear Rainforest: Balaenoptera physalus velifera in a Canadian Pacific fjord system

Fin whales (Balaenoptera physalus) are widely considered an offshore and oceanic species, but certain populations also use coastal areas and semi-enclosed seas. Based upon fifteen years of study, we report that Canadian Pacific fin whales (B. p. velifera) have returned to the Kitimat Fjord System (KFS) in the Great Bear Rainforest, and have established a seasonally resident population in its intracoastal waters. This is the only fjord system along this coast or elsewhere in which fin whales are known to occur regularly with strong site fidelity. The KFS was also the only Canadian Pacific fjord system in which fin whales were commonly found and killed during commercial whaling, pointing to its long-term importance. Traditional knowledge, whaling records, and citizen science databases suggest that fin whales were extirpated from this area prior to their return in 2005–2006. Visual surveys and mark-recapture analysis documented their repopulation of the area, with 100–120 whales using the fjord system in recent years, as well as the establishment of a seasonally resident population with annual return rates higher than 70%. Line transect surveys identified the central and outer channels of the KFS as the primary fin whale habitat, with the greatest densities occurring in Squally Channel and Caamaño Sound. Fin whales were observed in the KFS in most months of the year. Vessel- and shore-based surveys (27,311 km and 6,572 hours of effort, respectively) indicated regular fin whale presence (2,542 detections), including mother-calf pairs, from June to October and peak abundance in late August–early September. Seasonal patterns were variable year-to-year, and several lines of evidence indicated that fin whales arrived and departed from the KFS repeatedly throughout the summer and fall. Additionally, we report on the population’s social network and morphometrics. These findings offer insights into the dynamics of population recovery in an area where several marine shipping projects are proposed. The fin whales of the Great Bear Rainforest represent a rare exception to general patterns in this species’ natural history, and we highlight the importance of their conservation.